Endoscopes are elongate instruments navigable through natural body lumens and cavities of a patient for the purpose of remotely evaluating and treating a variety of ailments. Endoscopes have viewing capability provided by fiber optic elements that transmit images along their length to the medical care provider. Endoscopes may specifically configured in length, diameter, flexibility and lumen configuration to navigate specific treatment areas in the body. Examples of specifically configured endoscopes are a laparoscope, duodenoscope, colonoscope, sigmoidoscope, bronchoscope and urethroscope among others. In combination with remote viewing capability, endoscopes are frequently configured to provide a working channel through which shaft mounted tools and medical instruments may be navigated and remotely operated. Additionally, the endoscope shaft itself may carry a medical instrument for remotely performing a procedure at an internal treatment site, while permitting direct visualization of the site through the endoscope.
Presently, instruments and accessories used with endoscopes employ shafts that extend from the distal working end of the instrument, proximally outside of the patient to provide a mechanism by which the physician can manipulate the device. When used with an endoscope, the instrument shafts are routinely passed through the working channel of an endoscope so that the device extends distally to the distal face of the endoscope while the proximal end extends out through a port in the control handle of the endoscope to provide means for the physician to manipulate the instrument. In the case of certain endoscopic accessories, the distal end of the device attaches directly to the outside surface of the distal end of the endoscope. However, even with accessories that attach to the distal end of the endoscope, control elements such as cables or wires must pass through the working channel of the endoscope.
The arrangement of instruments and accessories passing through the working channel of the endoscope presents several problems to the user operating the combination. First, setting up the device can be cumbersome and time-consuming for the physician. In the use of accessories that attach to the distal end of the endoscope, the physician or technician preparing for the procedure must first back load control elements for the accessory into the working channel of the endoscope. This procedure entails threading the control cables or wires for the accessory into the working channel at the distal end of the endoscope and advancing the wires through until they project from a port at the control handle of the endoscope. After inserting the control elements through the working channel, the accessory may then be secured to the distal end of the endoscope. As a final step in the assembly, an accessory control module that will be manipulated by the physician during the procedure must be connected to the proximal end of the control element and then secured in some fashion to the endoscope control handle. The means for connecting such a control module to the endoscope control handle may be awkward and may not be secure because the accessory may not be designed for the particular endoscope control handle set-up.
After the lengthy set-up procedure described above, another problem faced by the physician during the procedure is controlling both the endoscope and the accessory at the same time. Typically, in an endoscopic procedure performed without an additional accessory, a physician will hold the endoscope control handle in the left-hand while advancing and controlling longitudinal movement of the shaft with the right hand, grasping the shaft along its midportion. When an accessory is added, the proximal control module presents the problem of operating a third element that must be manipulated by the physician's hand during the procedure. Obviously, with only two hands available, a physician must have the assistance of another person to control the endoscope accessory combination during the procedure. Alternatively, the physician will have to release control of one control element in order to manipulate the third element during various portions of the procedure. However, while the endoscope shaft or either the endoscope or accessory controls are released, that element will be subject to small undesired movements that may result in movement of the device away from the intended internal treatment site. It would be desirable to provide a system that permits two-handed control of both the endoscope and the accessory or instrument being used in conjunction with it.
Another disadvantage of current endoscopic accessories and instruments is that their control shafts must pass through a working lumen of the endoscope that could otherwise be used for other purposes during the medical procedure. In order to provide a reasonably small diameter, endoscopes can afford to provide only limited additional space for working channels to accept accessories or provide a lumen for other operations. Accordingly, when the control elements for a single accessory take up the space provided by the working channel, the use of other instruments or procedures through the channel are necessarily hindered or eliminated. With control elements for the accessory extending through the working channel, a second device, such as an injection needle for drug therapy will not be able to pass through the working channel and may, therefore, have to be navigated to the site with a second, subsequent intubation with the endoscope, which increases procedure time and danger to the patient. Additionally, functions such as aspiration are hindered by the presence of control elements in the working channel of the endoscope. With the diameter of the working channel being used predominantly by the indwelling control elements, vacuum through the channel is reduced and the aspirating function impaired. The reduced effectiveness of aspiration can be problematic in applications where blood and tissue may cover the distal end of the endoscope inhibiting viewing capability. Insufficient aspiration may not adequately clear the area of the distal end of the endoscope of tissue debris. Also, debris and blood that is sucked into the channel may interfere with the smooth operation of the accessory control elements. Additionally, procedures that require aspiration to collect areas of tissue into a chamber, such as band ligation or suturing may be negatively impacted by reduced aspiration capacity. Accordingly, it would be desirable to provide an endoscopic accessory control system that does not dominate the use of the endoscope's working channel.